Horne Engineering Ltd INSTALLATION, COMMISSIONING, OPERATING AND MAINTENANCE INSTRUCTIONS

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1 HORNE HEATSTAT T2-20 TMV2 Thermostatic Mixing Valve INSTALLATION, COMMISSIONING, OPERATING AND MAINTENANCE INSTRUCTIONS APPROVAL The HEATSTAT T2-20 TMV2 TMV has been independently tested by WRc-NSF and approved to the requirements of the TMV2 scheme. It has been tested against the requirements of both BSEN1287 (Low Pressure) and BSEN1111 (High Pressure). See Conditions of Use in this table. APPLICATION DESIGNATION HOT & COLD WATER FLOW PRESSURES MAXIMUM STATIC PRESSURE WATER SUPPLY TEMPS BSEN1287 Designation (Low Pressure) Washbasin Flow Series 80 Shower & sink Flow Series 100 Bidet Flow Series 125 Baths bar* Flow Series 250** bar ** ** The Heatstat T2 meets the bath flowrate requirements of BSEN1287 at 0.2 bar. 10 bar Hot C Cold <=25 C BSEN1111 Designation (High Pressure) All applications Flowrate Class D bar 10 bar Hot C Cold <=25 C * If either supply pressure is below 0.3 bar then the Hot & Cold supply pressures need to be balanced. Table 1 The HEATSTAT T2-20 TMV has a Designation of Use - HP & LP. Note that the minimum supply pressure for LP Tub application is 0.2 bar. The HEATSTAT T2-20 TMV is supplied with WRAS listed integral single check valves (springloaded, resilient trim in-line check valve cartridge with plastic guide and stem) located in each of the hot and cold water supply inlets. If the Heatstat T2-20 TMV is operated outwith these conditions it cannot be guaranteed to operate as a Type 2 TMV. The HEATSTAT T2-20 TMV is a Type 2 TMV and, as such, should not be used in Healthcare applications, where a Type 3 TMV must be used. Page 1 of 10

2 1 INSTALLING THE HEATSTAT T2-20 TMV Horne Engineering Ltd Installation must be in accordance with the Water Supply (Water Fittings) Regulations Check that the HEATSTAT T2-20 TMV is approved for the intended application. See Table 1 on Page 1 for approved designations. 1.2 The fitting of isolating valves on the hot and cold water inlet pipes is required. The fitting of strainers is recommended. The strainers should be fitted between the isolating valves and the HEATSTAT T2-20 TMV such that the isolating valves can be used to isolate the water supplies for checking and/or cleaning of the strainers. Note that an Installation Kit, Catalogue Code IK-21B, which provides integral isolation valves and strainers, is available. 1.3 The HEATSTAT T2-20 TMV can be fitted in any attitude with the mixed water outlet pointing upwards, downwards, horizontally or any angle between these planes. 1.4 Install the HEATSTAT T2-20 TMV with the Hot Water Supply connected to the valve inlet port identified with the red spot, and the Cold Water Supply connected to the valve inlet port identified with the blue spot. 1.5 When the HEATSTAT T2-20 TMV is installed, it must be accessible for maintenance, commissioning and testing. Leave at least 85mm clearance from the VALVE COVER (9) to permit the internals to be removed for servicing/maintenance. See Drawing 9310 on Page FLUSHING OF PIPEWORK Pipework must be flushed in accordance with Water Fittings Regulations 1999, schedule 2 G13.1 before connecting the HEATSTAT T2 TMV. The most common cause for complaint regarding the performance of any TMV is traced to dirt or debris in the TMV or check valves. DO NOT OPEN the hot water tap before flushing the hot and cold water pipework. A flushing Kit is available for use with the Installation Kit to provide means to conveniently flush the pipework. See Drawing 9365 on Page COMMISSIONING A NEW HEATSTAT T2-20 TMV 3.1 Ensure that the Hot Water Supply is connected to the port on the HEATSTAT T2-20 TMV identified with the red spot, and the Cold Water Supply to the port identified with the blue spot. Ensure that isolating valves (and also, preferably, strainers) are fitted. Open the hot water tap and allow water to run through the TMV. 3.2 Check that hot and cold water supplies temperatures and pressures are within the operating ranges (see Table 1 on Page 1 for details). 3.3 Measure the temperature at the hot water tap. This is the temperature of the mixed water. Ensure that the mixed water temperature is set appropriately, using the table below for guidance. APPLICATION BIDET SHOWER/SINK/WASHBASIN BATH RECOMMENDED MIXED WATER TEMPERATURES 38 C Max 41 C Max 44 C Max (see note) Note 46 C is the maximum mixed water temperature from the bath tap. The maximum temperature takes account of the allowable temperature tolerances inherent in Thermostatic Mixing Valves and temperature losses in metal baths. IT IS NOT A SAFE BATHING TEMPERATURE FOR ADULTS OR CHILDREN. The British Burns Association recommends C as a comfortable bathing for children. In premises covered by the Care Standards Act 2000, the maximum mixed water outlet temperature is 43 C. The mixed water temperature must never exceed 46 C. The maximum mixed water temperature can be 2 C above the recommended maximum set outlet temperature. Page 2 of 10

3 3.4 If necessary, make minor adjustments to the temperature setting as described in Section 4 below. 3.5 It is important to ensure that the TMV, rather than the water heater, is determining the mixed water temperature. To ensure this, adjust the mixed water temperature 5 C hotter than required and then bring the mixed water temperature DOWN to the required value. Never adjust UP to the required value. 3.6 N.B. The mixed water at the terminal fitting should never exceed 46 C. 3.6 CARRY OUT A COLD WATER ISOLATION TEST AS BELOW Close the cold water isolating valve and, after 5 seconds, measure the mixed water temperature. The flow of mixed water should immediately stop and then a drip or trickle may be seen. The temperature of any water coming from the tap should not be more than C above the mixed water set temperature measured in 3.3 above, and should not exceed 46 C If the HEATSTAT T2-20 TMV performs satisfactorily, close the hot water tap and open the cold water isolating valve If the water coming from the tap is at a temperature of more than C above the mixed water temperature setting, then the HEATSTAT T2-20 TMV is not shutting off the hot water supply properly. The most likely cause for this to happen is dirt inside the TMV. It should be dismantled and thoroughly cleaned and the pipework flushed again. See Maintenance Procedures. However, note that residual flow during this test is acceptable providing that the temperature of the water seeping from the valve is no more than 2ºC above the designated maximum mixed water temperature setting of the valve. 3.7 The HEATSTAT T2-20 TMV has now been commissioned. 4. TEMPERATURE ADJUSTMENT The HEATSTAT T2-20 TMV is set at the factory to control the mixed water temperature at approximately 44 C. Temperature should be adjusted on site to suit the application: see table below. APPLICATION BIDET SHOWER/SINK/WASHBASIN BATH MIXED WATER TEMPERATURE 38 C Max 41 C Max 44 C Max The range of temperature control is C. The set temperature must never exceed 46 C. It should be noted that the HEATSTAT T2-20 TMV requires a temperature differential of at least 5 C to work correctly (ie. the mixed water temperature must be at least 5 C lower than the hot water temperature and 5 C higher than the cold water temperature). To alter the temperature setting, carry out the following procedure. 4.1 Check that hot and cold water supply temperatures and pressures are within the operating ranges (see Table 1 on Page 1 for details). 4.2 Open the mixed water outlet and allow water to flow until the mixed water temperature has stabilised. Make sure that the dead leg from the HWS to the HEATSTAT T2-20 TMV and from the HEATSTAT T2-20 TMV to the outlet has fully cleared. Page 3 of 10

4 4.3 Using a spanner, turn the ADJUSTING SCREW (1) clockwise to reduce the mixed water temperature or anti-clockwise to increase it. Adjustments of not more than half a turn at a time should be made. The temperature at the outlet should be measured and allowed to stabilise after each adjustment. 4.4 After making an adjustment, close the hot water supply isolating valve for ten seconds then reopen it and measure the mixed water temperature again. If a further adjustment is required, repeat the procedure. 5. IN-SERVICE TESTING 5.1 Periodic testing should be carried out to check whether or not any deterioration has occurred in the performance of the HEATSTAT T2-20 TMV. The Mixed Water Temperature must be verified against the original set temperature at least once a year. Check the temperature at a normal flow rate after the system has stabilised. 5.2 A COLD WATER ISOLATION TEST should be carried out as described in above. If the water coming from the tap is at a temperature of more than 2 C above the mixed water temperature setting then the HEATSTAT T2-20 TMV is due for maintenance. If there is no significant change to the set outlet temperature (i.e. it is within ±2 C of original setting) and the cold water isolation test is satisfactory, then the valve is working correctly and no further service work is required. NOTE: A TMV in need of maintenance can be undetectable in normal use and only become apparent when a disruption occurs in the hot or cold water supply pressures or temperatures. 5.3 The frequency of in-service testing depends upon the condition of the water passing through the TMV. In-service testing must be carried out more frequently in hard water areas than in soft water areas. As a general guide, in-service testing should be carried out at intervals somewhere between six months and twelve months. In-service testing should be carried out at least every twelve months and, where the water is hard, the interval may be less than six months. Experience of local conditions and the in-service testing record will dictate the frequency of in-service testing. 6. MAINTENANCE Maintenance of all TMVs is essential. If a TMV does not operate properly, there is a risk of someone being scalded. The frequency of maintenance depends upon the condition of the water passing through the TMV. The remarks in 5.3 regarding in-service testing apply equally to maintenance. 'O' Ring Seals should be replaced at least every three years. The THERMOSTAT ELEMENT/SLIDEVALVE ASSEMBLY (5) should be replaced at least every six years. Service Kits containing thermostat element assembly and/or seals are available. All other parts should be replaced only if physical damage has occurred. MAINTENANCE PROCEDURES 6.1 Close hot and cold water inlet isolating valves and open the outlet to allow pipework to drain. 6.2 TMV MECHANISM Minor maintenance carried out with the HEATSTAT T2-20 TMV in situ Unscrew VALVE COVER (9). Lift out the THERMOSTAT ELEMENT/SLIDEVALVE ASSEMBLY (5) The THERMOSTAT ELEMENT/SLIDEVALVE ASSEMBLY (5) is a precision part and must be handled with care. In particular, only ever lay it down on a clean soft surface, e.g. a towel. Ensure that it does not become contaminated with dust or dirt or the TMV will not pass the Cold Water Isolation Test Remove the ADJUSTING SCREW (1) by turning it clockwise until the thread disengages and it comes out the underside of the VALVE COVER (9). Page 4 of 10

5 6.2.4 The SLIDE VALVE SEAL (4) can be removed by piercing the rubber with a sharp pointed probe. Take care not to damage the edges of the groove If the SLIDE VALVE SEAL (4) has been removed, then it MUST be replaced with a new one. NEVER re-use an 'O' Ring Thoroughly clean all components in clean water Flush out the valve body by replacing the VALVE COVER (9) and ADJUSTING SCREW (1) by opening the isolating valves and allowing water at full bore to pass through the body to the outlet If dirt is seen during flushing then carry out FLUSHING PROCEDURE in Section Re-assemble the HEATSTAT T2-20 TMV. Recommission the TMV (See Section 3). 6.3 MAJOR MAINTENANCE. For this, remove the HEATSTAT T2-20 TMV from the pipework Unscrew pipe COUPLING NUTS (14) and the outlet pipe coupling Lift the valve out of the pipework DO NOT grip the valve body in a vice. This could distort the body and jam the internal parts Remove the valve cover and internal parts as referred to in to If the valve body requires de-scaling, remove all O-Ring seals and use a proprietary fluid for this purpose. Do not put the THERMOSTAT ELEMENT/SLIDEVALVE ASSEMBLY (5) in de-scaling fluid Inspect the condition of the "HOT VALVE FACE" in the Valve Body (10) and the "COLD VALVE FACE" on the Valve Cover (9). (See Drawing 9309 for location of these faces). If the valve faces show signs of deterioration, they can be resurfaced as follows Using a mandrel (Tool No.6356), lap the HOT VALVE FACE using a water soluble scouring paste (e.g. toothpaste) Carefully inspect the condition of the upper and lower faces of the slidevalve on the THERMOSTAT ELEMENT/SLIDEVALVE ASSEMBLY (5). Gently run a fingernail around the sealing faces. Any nicks or grooves on these surfaces mean that the slidevalve must be replaced with a new one Reassemble the HEATSTAT T2-20 TMV. Recommission the TMV (See Section 3). 6.4 RE-ASSEMBLY Replace the O rings. When fitting new O-Rings, it is advisable to smear them sparingly with a WRAS listed silicone grease Insert the components into the HEATSTAT T2-20 TMV in the location shown on Drawing Insert the ADJUSTING SCREW (1) into the VALVE COVER (9) and turn anti-clockwise until the first thread of the ADJUSTING SCREW (1) is just visible at the top of the VALVE COVER (9) When the internal components have been located loosely in the valve body, place the VALVE COVER (9) in place and then push gently and turn until the thread on the VALVE COVER (9) engages with the VALVE BODY (10). The internal components are self-aligning. 6.5 CHECK VALVES Check valves are located within the PIPE COUPLINGS (15). They are not removable. They are designed for a long, maintenance-free life. 6.6 After any maintenance work, recommission the TMV (See Section 3). Page 5 of 10

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9 FAULT FINDING CHART Horne Engineering Ltd SYMPTOM POSSIBLE CAUSE ACTION Mixed water temperature too high Mixed water temperature too low Mixed water flow rate too low. Mixed water temp does not respond to adjusting screw Mixed water temp changes and is not steady Water at outlet runs full hot or full cold Valve continues to pass cold water when hot supply is isolated Temperature setting too high. Temperature has been set when hot water supply temperature was too low Hot water supply has migrated into cold water supply Thermostat Element has failed. This can be checked by carrying out a hot or cold water isolation test. Hot valve face requires cleaning Temperature Setting too low Hot water supply temperature has fallen. Cold water has migrated into hot supply Re-adjust temperature setting with hot water supply at correct temperature. Inspect Check Valve (16) at cold inlet. If the check valve leaks replace the pipe coupling (15) and check valve subassembly. Replace Thermostat Element/Slidevalve assembly (5) Remove Valve Cover (9) and internals and clean Hot Valve Face. REFER TO SECTION 4 See Drg Re-adjust temperature setting 4 Feel hot water supply pipe near to valve with outlet running. Check hot water supply system. Inspect Check Valve (16) at hot inlet. If the check valve leaks replace the pipe coupling (15) and check valve subassembly. Remove valve Cover (9) and clean up valve face 3.2 See Drg 9309 Cold valve face requires cleaning Partly blocked strainers Clean strainers - Unusually high pressure drop in supply pipework - Extra Demand added to system Thermostat Element/Slide- Valve assembly (5) is seized Hot and cold inlets reversed Thermostat Element/Slide- Valve assembly (5) is seized Thermostat element has failed. (This can be checked by carrying out a hot or cold water isolation test) Hot and cold inlets are reversed Cold valve face requires cleaning Check all valves are full open. Check Pressurisation unit. Check mains supply Check pipe sizing - Valve requires de-scaling Remove HEATSTAT T2 TMV from pipes and reverse connections. Connect inlet with red dot to hot pipe Valve requires De-Scaling Replace Thermostat Element /Sidevalve assembly (5) Correct the inlet connections. Hot inlet is marked Red. Cold inlet is marked Blue. Remove valve cover (9) and service cold valve face Page 9 of 10

10 Valve continues to pass hot water when cold supply is isolated. Horne Engineering Ltd Fouling at hot valve seat Clean hot valve face Slide-Valve seal is damaged Replace Slide-Valve Seal (4) & Element has failed If water flowing is more than 4 C above required mixed water temperature then valve may not have been commissioned with an adequate hot water supply temperature. NB If this is the case the valve may not offer scald protection Replace Thermostat Element/ Slidevalve Assembly (5) Recommission the valve, closely following the guidance in Section If water flowing is not more than 4 C above required mixed water temperature then the boiler is not heating the water supply sufficiently to cause thermal shut-off. (N.B. this is possible with combi boilers). Repeat test with hot water temperature at least 5 C above required mixed water temp. Page 10 of 10